Another plot might involve them teaming up against a common enemy. Maybe a dark wizard is targeting them because of their combined magical abilities and they have to use their brotherly bond to overcome the threat. They could learn new spells together and support each other in battles.
A really engaging plot could be their journey to find out about their family history. Since they are brothers in this fanfiction, there must be a story behind it. They could go on adventures, exploring old family mansions or seeking out old relatives who can tell them more about their parents and how they came to be separated in the first place.
One interesting plot could be them growing up together in a magical world. They discover a hidden part of Hogwarts that has been forgotten for centuries. They use their combined skills, Harry's courage and Cedric's intelligence, to solve the mysteries within it.
One possible plot could be that they discover they are brothers early on in their Hogwarts years. This leads to them having to navigate the complex wizarding world together, facing the challenges of Voldemort's return side by side. They combine their different skills, Harry's Gryffindor courage and Blaise's Slytherin cunning, to outwit the Death Eaters at every turn.
There could also be other important characters. For instance, Hermione and Ron could play significant roles. They might be initially skeptical about Blaise being Harry's brother but then come to accept and support the new family dynamic. And Dumbledore could also be involved, guiding the two brothers in understanding their new relationship and the implications it has for the wizarding world.
Another plot could be that they find out they are related in a more profound way than just being friends. This discovery could lead to them exploring their family histories together and uncovering secrets that change their understanding of the wizarding world and their place in it.
A great plotline might involve a magical competition where Draco, Blaise, and Harry are all forced to compete. As they face various challenges, they start to understand each other better. For example, they realize that they all have the same fears about the future of the wizarding world. It could also be a plotline where they are all transported to an alternate dimension and have to rely on each other to get back home.
One common plot is that Blaise and Draco initially notice Harry's abuse in a somewhat accidental way, like during a Hogwarts event or in a shared class. They then decide to keep an eye on him secretly. As they get to know Harry better, they realize the extent of his abuse and start taking more direct actions to protect him, such as standing up to his abusers or finding ways to get him away from dangerous situations.
A possible plotline is dealing with the media in the wizarding world. As Harry is a very well - known figure, their marriage would be big news. There could be tabloids writing all sorts of things about them, and they would have to handle the public scrutiny. Also, a plotline could involve them mentoring young wizards. Their unique relationship could be an example for the younger generation to learn about acceptance and different kinds of love. And they could pass on their magical skills in a new and innovative way.
At first, it might be a bit rocky. Harry, being a Gryffindor, and Blaise, a Slytherin, have different outlooks. But as brothers, they'd gradually start to understand each other more. They'd probably become protective of one another and support each other in the face of danger.
Maybe in the fanfiction, their brotherhood is tested when they are forced to make difficult choices. For example, a powerful villain offers one of them a deal that could save their village but at the cost of betraying the others. Gaara, with his experience of being an outcast and then a leader, could be the one to find a solution that doesn't involve betrayal. Naruto would be all for sticking together no matter what, while Sasuke might be more tempted by the power the deal offers.
One plot idea could be a story where Blaise and Draco have to team up with Harry and Hermione for a special magical tournament. They start off as reluctant allies but gradually learn to respect each other's skills. Another could be a mystery - something strange is happening at Hogwarts and the four of them must put aside their differences to solve it. For example, students are losing their magical abilities one by one, and they suspect a dark magic artifact hidden in the castle.